1. Field of the Invention
The present invention generally relates to an optical information recording apparatus, and particularly relates to the driving apparatus for the light source which emits a light beam for recording.
2. Description of the Prior Art
In an optical information recording apparatus, generally, the duty ratio of the recording signal is fixed at 50%, and information is recorded by intermittently irradiating the information recording surface of a recording disk (hereinafter, simply referred to as a disk) with a recording light beam in accordance with the duty ratio. In a CAV disk (with fixed angular velocity). the linear velocity is different between inner and outer circumferences of the disk, and when the linear velocity is increased, the recording sensitivity is reduced. The reduction of the recording sensitivity with increasing linear velocity has been compensated by increasing the light power (the intensity of the light). that is, the recording power, of the recording light beam.
However, the power of the light emitted from a light source of a recording light beam, for example, a semiconductor laser, is limited, and therefore in a region beyond the output limitations of the light source, the reduction in sensitivity cannot be sufficiently compensated. As a result, in a high linear velocity region, the recording sensitivity has been frequently insufficient. If the recording sensitivity is low, the center of the so-called eye pattern of the reproduced waveform is displaced from a judgment reference level, and therefore a high-quality reproduced signal cannot be obtained.